Lithium-organic electrolyte cells have been known. Such cells employ an electrolyte which may be for example propylene carbonate, dioxolane, tetrahydrofuran, dimethoxyethane, etc. The organic electrolyte contains a dissolved lithium salt which may for example be lithium perchlorate, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium aluminum tetrachloride, lithium thiocyanate, etc. The cathode employed may for example be a material such as iron sulfide (FeS). In cells to which the invention is directed, the anode polarizes more than does the cathode during a pulse discharge. The concentration of lithium salt in the electrolyte would generally range from about 1 to about 3 molar.
The art has recognized heretofore that problems exist in using lithium as the anode in organic electrolyte cells. These problems have to do with the reactivity of lithium, the formation of lithium compound films on the surface of the lithium anode during use, and the low surface area of lithium foils. Such features lead to adverse electrochemical effects such as lower discharge rates and insufficient voltage on pulse discharge.
It has been proposed in U.S. Pat. Nos. 4,002,492 and 4,056,885 to employ lithium-aluminum alloys as anodes in organic electrolyte cells. Thus, U.S. Pat. No. 4,002,492 describes use of a lithium-aluminum alloy containing about 63% to about 92% lithium on an atomic basis.
U.S. Pat. No. 4,056,885 describes the production of a lithium-aluminum alloy on the surface of a lithium electrode by the practice of laminating aluminum foil to the lithium anode and exposing the perforated foil to the action of the electrolyte containing a lithium salt. Alloying of the lithium and aluminum is said to begin in times of up to about 24 hours.